Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-02-08
Mon.Not.Roy.Astron.Soc.407:420,2010
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
17 pages, 14 figures, matches version accepted for publication in MNRAS
Scientific paper
10.1111/j.1365-2966.2010.16914.x
We measure the angular auto-correlation functions (w) of SDSS galaxies selected to have photometric redshifts 0.1 < z < 0.4 and absolute r-band magnitudes Mr < -21.2. We split these galaxies into five overlapping redshift shells of width 0.1 and measure w in each subsample in order to investigate the evolution of SDSS galaxies. We find that the bias increases substantially with redshift - much more so than one would expect for a passively evolving sample. We use halo-model analysis to determine the best-fit halo-occupation-distribution (HOD) for each subsample, and the best-fit models allow us to interpret the change in bias physically. In order to properly interpret our best-fit HODs, we convert each halo mass to its z = 0 passively evolved bias (bo), enabling a direct comparison of the best-fit HODs at different redshifts. We find that the minimum halo bo required to host a galaxy decreases as the redshift decreases, suggesting that galaxies with Mr < -21.2 are forming in halos at the low-mass end of the HODs over our redshift range. We use the best-fit HODs to determine the change in occupation number divided by the change in mass of halos with constant bo and we find a sharp peak at bo ~ 0.9 - corresponding to an average halo mass of ~ 10^12Msol/h. We thus present the following scenario: the bias of galaxies with Mr < -21.2 decreases as the Universe evolves because these galaxies form in halos of mass ~ 10^12Msol/h (independent of redshift), and the bias of these halos naturally decreases as the Universe evolves.
Brunner Robert J.
Percival Will J.
Ross Ashley J.
No associations
LandOfFree
Evolution of the Clustering of Photometrically Selected SDSS Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evolution of the Clustering of Photometrically Selected SDSS Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of the Clustering of Photometrically Selected SDSS Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-307307